The Bible of 3D Printing
Known worldwide for his expertise in rapid prototyping and manufacturing, Terry Wohlers writes an industry report describing the applications, players, technologies and past, present and future of 3D printing. For more information, visit www.wohlersassociates.com.
Chuck Hull of 3D Systems, who pioneered rapid prototyping in the mid-1980s, is pictured in front of a stereolithography apparatus (SLA). Prototypes and parts are built from a liquid photopolymer, and each layer is created by a UV laser that cures one cross section at a time. At the end of the job, the whole part is cured once more after excess resin and support structures are removed. (Image courtesy of 3D Systems, Inc., www.3dsystems.com)
Laser sintering machines build prototypes and final parts from powdered plastics and metals that are heated by a laser. At the end of the job, the excess powder is removed and recycled for the next build. This metal part was created in a 3D Systems Sinterstation using the company's LaserForm resin. (Image courtesy of 3D Systems, Inc., www.3dsystems.com)
Fused Deposition Modeling (FDM)
FDM machines deposit ABS plastic or another type of thermoplastic through a heated nozzle to form the layers. After being extruded, the plastic solidifies. Developed by Scott Crump of Stratasys in the late 1980s, FDM is a popular technology for making prototypes. This shows a close-up of the print head of a Dimension FDM machine from Stratasys (www.dimensionprinting.com).
Electron Beam Melting (EBM)
Using an electron beam that melts metal powder a layer at a time in a vacuum chamber, EBM machines are used to create titanium and cobalt chrome parts. Conventional machining may be required to finish the goods. These engine parts were made with Arcam's CAD to Metal system. (Image courtesy of Arcam AB, www.arcam.com)
Color 3D Printing
The 3D printers from Z Corporation (www.zcorp.com) jet color binders onto powdered, composite materials one layer at a time, enabling the fabrication of fully printed prototypes. All the gears and rods in this demonstration model were created in place as a single unit from bottom to top. At the end of the job, the excess powder was removed between the gears. When any single gear is moved manually, all the others rotate simultaneously.
Jetting Liquid Polymer
Similar to inkjet printers, Objet's PolyJet piezoelectric print heads use thousands of nozzles to jet 16 micron layers of photopolymer that are immediately cured by UV light. The model material for the part and the support material that fills the voids come from different nozzles. Because of its 600x600 dpi resolution, PolyJet machines make fast prototypes. (Image courtesy of Objet Geometries Ltd., www.2objet.com)
From CAT scans and MRIs to physical 3D models, surgeons can preview a patient's bones and organs and save hours of time at the operating table. In addition, 3D printers can make generic and custom implants. The model of a human spine (top) was created by Objet's PolyJet technology, while the bottom image shows a finished Stryker knee implant made out of cobalt chrome in a laser sintering machine from Electro Optical Systems (EOS). (Images courtesy of Objet Geometries Ltd. and EOS GmbH.)
A Desktop Breakthrough
At $4995, the Desktop Factory is a breakthrough in low-cost 3D printers. Expected in 2008, the technology fuses 10 mil layers of powdered plastic by light, somewhat like a laser printer. Targeted at $1 per cubic inch, it is also a breakthrough in less costly 3D printer consumables. (Images courtesy of Desktop Factory, Inc., www.desktopfactory.com)
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